java itextpdf 를 이용하여 테이블을 가진 pdf 다운로드 구현하기

1. Gradle 설정 추가

 comlile('com.itextpdf:itextpdf:5.5.13')

 - Gradle 이외 설정은 mvnrepository 참조 (https://mvnrepository.com/artifact/com.itextpdf/itextpdf/5.5.13)

 - AGPL 라이센스임에 주의! 네트웍 서비스에 이용하는 경우에도 소스를 공개하여야 함 ㄷㄷ

2. pdf document 생성 및 download 처리

public ResponseEntity<InputStreamResource> downloadPDF() {
        
        List<TableData> tableDataList = getTableData();  // 각자..
        ByteArrayInputStream inputStream = generatePDF(tableDataList);
        String filename = String.format("download_test_%s.pdf", LocalDateTime.now().toString("yyyy-MM-dd"));

        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition", "inline; filename=" + filename);

        return ResponseEntity.ok()
                .headers(headers)
                .contentType(MediaType.APPLICATION_PDF)
                .body(new InputStreamResource(inputStream));
}


private ByteArrayOutputStream generatePDF(List<TableData> tableDataList) {

        Document document = null;
	ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

	try {
		document = new Document();

		// 한글 처리를 위한 글꼴 설정 추가
		String fontPath = "/static/css/fonts/malgun.ttf";
		BaseFont bf = BaseFont.createFont(fontPath, BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);

		Font titleFont = new Font(bf, 15, Font.BOLD);
		Paragraph title = new Paragraph("문 서 제 목", titleFont);

		Font subTitleFont = new Font(bf, 14, Font.NORMAL);
		DateFormat titledf = new SimpleDateFormat("yyyy-MM-dd");
		Paragraph subTitle = new Paragraph("문서 소제목", subTitleFont);

		PdfPTable table = new PdfPTable(6);
		table.setWidthPercentage(100);
		table.setWidths(new int[] { 2, 2, 3, 2, 4, 4 });

		Font headFont = new Font(bf, 11, Font.BOLD);
		table.addCell(setHeadCell("필드1", headFont));
		table.addCell(setHeadCell("필드2", headFont));
		table.addCell(setHeadCell("필드3", headFont));
		table.addCell(setHeadCell("필드4", headFont));
		table.addCell(setHeadCell("필드5", headFont));
		table.addCell(setHeadCell("필드6", headFont));

		DateFormat df = new SimpleDateFormat("yyyy-MM-dd/HH:mm:ss");
		for (TableData tableData : tableDataList) {
			table.addCell(setChildCell(tableData.getField1() == null ? "-" : tableData.getField1()));
			table.addCell(setChildCell(tableData.getField2() == null ? "-" : tableData.getField2()));
			table.addCell(setChildCell(tableData.getField3() == null ? "-" : tableData.getField3()));
			table.addCell(setChildCell(tableData.getField4() == null ? "-" : tableData.getField4()));
			table.addCell(setChildCell(tableData.getField5() == null ? "-" : tableData.getField5()));
			table.addCell(setChildCell(tableData.getField6() == null ? "-" : tableData.getField6()));
		}

		PdfWriter.getInstance(document, outputStream);

		document.open();
		document.add(title);
		document.add(new Paragraph("\\n"));
		document.add(subTitle);
		document.add(new Paragraph("\\n"));
		document.add(table);

	} catch (DocumentException | IOException ex) {
		log.error("PDF 파일 생성 실패");
	} finally {
		if(document != null) {
			document.close();
		}
	}

	return new ByteArrayInputStream(outputStream.toByteArray()); 
}

private PdfPCell setHeadCell(String content, Font font) {
	PdfPCell hcell = new PdfPCell(new Phrase(content, font));
	hcell.setVerticalAlignment(Element.ALIGN_MIDDLE);
	hcell.setHorizontalAlignment(Element.ALIGN_CENTER);
	hcell.setBackgroundColor(new BaseColor(226, 226, 226));
	hcell.setFixedHeight(25f);
	return hcell;
}

private PdfPCell setChildCell(String content) {
	PdfPCell cell = new PdfPCell(new Phrase(content));
	cell.setVerticalAlignment(Element.ALIGN_MIDDLE);
	cell.setHorizontalAlignment(Element.ALIGN_CENTER);
	cell.setFixedHeight(20f);
	return cell;
}